ACTRIS Contributes to Global EarthCARE Calibration and Validation Effort

A recent article published by the European Space Agency (ESA) highlights the major international efforts supporting the EarthCARE (Earth Clouds, Aerosols and Radiation Explorer) mission, including the crucial role played by ACTRIS and its coordinated network of atmospheric research facilities.

Since EarthCARE’s launch, its four sophisticated instruments have been collecting data to better understand how clouds and aerosols influence Earth’s radiation budget—a key aspect of climate regulation. To ensure the accuracy and scientific value of this data, ESA has organized an ambitious calibration and validation (Cal/Val) programme involving aircraft, maritime, and ground-based campaigns.

The largest ground-based contribution during EarthCARE’s first year of operation came from ACTRIS, through its involvement in the ATMO-ACCESS pilot project. Over 40 ACTRIS ground-based stations across Europe, equipped with state-of-the-art lidar and radar instruments, provided long-term, high-resolution measurements of aerosol and cloud properties. These stations were strategically aligned with EarthCARE satellite overpasses, creating a powerful platform for cross-validation.

ACTRIS Central Facilities supported the campaign by offering calibrated reference data, expert services, and quality assurance, further strengthening the mission’s scientific output. Collaborations with other networks, such as EARLINET and MPL-Net, contributed to a shared repository of validation data and a truly integrated observing system.

ESA’s recognition of ACTRIS as a key Cal/Val partner reflects the infrastructure’s growing relevance for satellite validation and Earth system monitoring. The data collected will help refine EarthCARE algorithms and enhance the reliability of climate and weather models worldwide.

Read the full ESA article here: Global EarthCARE cal/val effort to boost mission success